Pressure sensors are typically used to measure the pressure of a liquid or a gas, such as air. Pressure sensors typically provide an output signal that varies based on the pressure sensed by the pressure sensor. One type of pressure sensor includes a stand-alone pressure sensor that is coupled to or bonded to a sensor circuit, such as an application-specific integrated circuit (ASIC). This type of pressure sensor is expensive to fabricate. Connecting this type of pressure sensor to a sensor circuit is also expensive. Another type of pressure sensor is a pressure capsule (e.g., a polysilicon plate) that is integrated with a sensor circuit, such as an ASIC, during a back-end-of-line (BEOL) process. This type of pressure sensor is also expensive to produce since several additional mask levels are used to fabricate the pressure sensor and the pressure sensor uses a significant amount of space of the ASIC.
For these and other reasons, there is a need for the present invention.